Yeah, I had a problem with this as well and would advise caution. I was able to plug in my Glaive and keep trying. iCUE created a duplicate M65 in the device list with some garbled name, but that was the actual device. Lots of unplugging and replugging. Finally got it. First firmware update in a long time. Would like to know what it does, especially since there appears to be some risk.

Yep ! When i unplugged and replugged my M65 it's show me in the ICUE a other K70.
In other words i have a k70 that is actually the M65 mouse.

So you solve it only with unplugging and replugging it @c-attack ?

Unplugging and re-initiating the firmware upgrade. Fail. Unplug an try and again. Just brute force, no brains. Sorry.

I would be more inclined to unplug the device and force a shutdown (or exit of CUE) than to persist trying to update. Obviously if you got stuck halfway between and have a disabled mouse, that doesn't help and you might want to try the persistent approach. I think at this point the smarter play is back out and wait, if possible.

1: Unplug your mouse from the computer.
2: Locate the small pinhole underneath your mouse. For some, this will be located directly on the bottom in plain sight. On others, it will be located underneath one of the removable weights attached to the bottom of the mouse. ( THE TOP RIGHT )
3: Using a small paperclip or push-pin, press down on the button inside the pinhole.
4: Plug your mouse back into the computer, while holding down the pinhole button.
5: Once it is plugged back in, your computer should recognize a drive called CRP_Disabled. Please open this.
6: Download the files from the link below.
7: Delete the file FIRMWARE.BIN from the CRP_DISABLED drive, and then place the file with ISP in it’s name to the CRP_Disabled drive.
8: Once you have performed the steps above, please unplug your mouse and then plug it back in. The device will then return to normal.